Growth and gonad production of the sea urchin Hemicentrotus pulcherrimus in the fucoid bed and algal turf in northern Japan     

Yukio Agatsuma  Nobuyasu Nakabayashi  Nobuaki Miura  & Kazuya Taniguchi 《Marine Ecology》2005,26(2):100-109

To clarify the differences in the growth and gonad size of the sea urchin Hemicentrotus pulcherrimus among algal sere, the study was conducted in June and July, and September 1998 at three fucoid beds in Oga and at three algal turfs in Hachimori, Akita Prefecture in northern Japan. The most rapid growth was observed in a large perennial fucoid bed at the climax stage. Growth in a small perennial Chondrus ocellatus‐dominated bed in algal turfs in the seral stage was then high. The slowest growth was observed in the small perennial Dictyopteris divaricata‐ and Laurencia spp.‐dominated beds which are known to possess chemicals which act as feeding deterrents against the sea urchins. The gonad index (gonad wet weight × 100/body wet weight) at a fucoid bed was high where standing crops exceeded 3 kg·m^?2. The gonad index in the Laurencia bed was lower than those at fucoid beds. These results suggest that growth and gonad production are affected by algal sere and differ among species of small perennial algae in the seral stage with or without chemical defense.  相似文献   

Trends in age-composition, growth and reproductive parameters of Barents Sea harp seals, Phoca groenlandica     

Kjellqwist  Sten Anders; Haug  Tore; Oritsland  Torger 《ICES Journal of Marine Science》1995,52(2):197-208

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The role of sex change, growth and mortality in Pandalus population dynamics and management     

Fu  Caihong; Quinn  Terrance J.  II; Shirley  Thomas C. 《ICES Journal of Marine Science》2001,58(3):607-621

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Fishing, selection, and phenotypic evolution   总被引：10，自引：9，他引：10  

Law  Richard 《ICES Journal of Marine Science》2000,57(3):659-668

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池沼公鱼耳石日轮的观察研究   总被引：7，自引：0，他引：7  

解玉浩  李勃  王国恩 《海洋与湖沼》1995,26(4):402-407

于1989年3－8月，从辽阳汤河水库捕取成熟的池沼公鱼，获得人工授精卵。用压片法光镜下连续观察胚胎发育后期和前仔鱼期耳石轮纹的形成，并采集已知月龄的幼、成鱼耳石，制片镜检轮纹数量和排列。结果表明，仔鱼在印黄接近吸收完并开始摄食外界食物时，即孵出后第6d至第7d形成第1个轮纹，之后每天一轮，这些轮纹就是日轮；日轮间距呈规律性变化，这些变化与鱼体生长发育及生态条件密切相关。  相似文献   

南海甲藻卡氏前沟藻的生长特性研究   总被引：1，自引：0，他引：1  

孙海燕  龙丽娟  吴军 《热带海洋学报》2006,25(6):68-71

从海南省三亚海域收集分离了甲藻卡氏前沟藻Amphidinium carterae藻种,并在实验室成功进行了人工培养,同时对其生长特性进行了研究。实验结果表明,接种初始的细胞密度对其生长率和最高细胞密度影响很小,实验室培养和大量养殖可以采取低密度接种;最适宜培养的环境条件盐度为34,温度为26℃,营养盐浓度为2K。在温度为18—30℃、盐度为26—42、K培养液浓度系列为1/16—2 K的条件下都可存活,最大指数期平均生长率为0.958分裂.d-1,获得的最大细胞密度为7.27×105cells.ml-1。实验结果与属温带的胶州湾同物种对比,表明该藻种生长特性与温带品系有明显差异。  相似文献   

半连续培养下东海原甲藻和中肋骨条藻种群生长过程与种间竞争研究   总被引：17，自引：0，他引：17  

王宗灵  李瑞香  朱明远  陈炳章  郝彦菊 《海洋科学进展》2006,24(4):495-503

采用半连续培养方法研究了温度和营养盐(N和P)限制对中国东海2种重要赤潮生物东海原甲藻和中肋骨条藻生长及种间竞争的影响。结果表明,东海原甲藻在20℃和25℃时生长状态良好,具有明显的指数增长期,15℃时细胞生长明显受到影响;中肋骨条藻具有较广的温度适应性,15~25℃时均具有明显的指数增长期。东海原甲藻可以忍受低营养盐环境并种群增长,而中肋骨条藻细胞增长需要较丰富的营养盐。在营养盐充足的环境里中肋骨条藻具有竞争优势,相反,在营养盐限制的环境中,东海原甲藻是竞争的优胜者。实验结果与东海原甲藻赤潮爆发现场的环境调查结果基本一致,可以作为解释东海原甲藻赤潮形成原因的依据。  相似文献   

The annual cycle of Synechococcus (cyanobacteria) in the northern Levantine Basin shelf waters (Eastern Mediterranean)   总被引：1，自引：0，他引：1  

Zahit Uysal  & &#;rem Köksalan 《Marine Ecology》2006,27(3):187-197

Abundance of picoplanktonic chroococcoid marine cyanobacteria Synechococcus was monitored weekly over the year 1998 in shallow coastal waters of the northern Levantine Basin. The ambient physical, chemical and biological variables (temperature, salinity, Secchi disk depth, total suspended sediment, nitrate, phosphate, Chl a and phytoplankton) were also measured. Synechococcus was found to be more abundant during summer and early autumn and less during winter and early spring. At the surface and 15 m depth, cell concentrations were in the range 6.4 × 10³–1.5 × 10⁵ and 3.2 × 10³–1.6 × 10⁵ cells·ml⁻¹, respectively. Based on the Pearson product–moment correlation analysis, a highly significant correlation between Synechococcus abundance and ambient temperature was observed (n = 40, r = 0.558, P < 0.01). As Synechococcus forms blooms that usually do not last more than a week, the short time‐scale survey achieved in this study was appropriate to reveal its abundance dynamics. Several factors such as rapid changes in nutrient concentration (especially nitrate), phytoplankton, light availability, temperature, salinity, freshwater input and vertical mixing played a relevant role on the abundance of Synechococcus over the year in the highly dynamic shallow coastal waters of the Levantine Basin.  相似文献   

Targeted environmental monitoring for the effects of medicines used to treat sea-lice infestation on farmed fish   总被引：1，自引：0，他引：1  

Davies  I. M.; Rodger  G. K.; Redshaw  J.; Stagg  R. M. 《ICES Journal of Marine Science》2001,58(2):477-485

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Factors involved in growth plasticity of cockles Cerastoderma edule (L.), identified by field survey and transplant experiments     

Xavier De Montaudouin 《Journal of Sea Research》1996,36(3-4)

In Arcachon Bay, a macrotidal coastal lagoon in southwest France, growth rates of cockles Cerastoderma edule (L.) differ greatly between locations. Sampling of populations at different tidal levels showed that the mean shell length was significantly and positively correlated with immersion time, whereas no correlation was found with population density and microphytobenthos biomass. Transplants of cockles between two intertidal sites were used to examine the relative importance of habitat and site of origin for growth rate and condition index. Artifacts due to manipulation were assessed, i.e. the impact of enclosures on growth, conditon index and mortality. During a 5-mo reciprocal transplant experiment, growth rates of the transplanted cockles and the cockles already present were similar, whereas the sites of origin did not affect growth rate. Condition index, however, displayed significant differences in relation to both transplant and origin sites. During a further 6-mo experiment in which cockles were transplanted from one site to four new sites, growth was mainly influenced by tidal level. These results indicate that net growth started when cockles were immersed 30% of the time. It is concluded that, on the scale of Arcachon Bay (156 km²), differences in growth and condition between cockle populations are largely phenotypic. Tidal level (i.e. food supply and emersion stress) accounts for most of these differences, but the existence of genetically or physiologically different populations cannot be excluded.  相似文献